WPR16FA029

The pilot's loss of control during landing on a dolly. Contributing to the accident were the pilot's decision to conduct the flight without an instructor despite multiple flight instructors' recommendations to the contrary, his failure to land on the ramp when he experienced difficulty landing on the dolly, and his impaired decision-making, judgment, and psychomotor performance, due to his use of a combination of two psychoactive drugs.

The private pilot and the pilot-rated passenger departed for a flight in the pilot's newly purchased helicopter. The pilot practiced several landings in a field during the flight and then flew back to the departure airport, where the approach and hover taxi to the ramp were uneventful. The pilot made a landing attempt on a dolly but landed only partially on the dolly, which caused the helicopter to pitch nose up and strike the ground with its tail. The helicopter hit the dolly with such force that the dolly broke free from the chocks securing it and spun around. The helicopter climbed and spun upwards aggressively but stabilized after rotating 270° to the right. The pilot then landed the helicopter in an abnormal location that straddled the ramp and a taxiway. Ground crew personnel re-secured the dolly with chocks, and, after about 2 1/2 minutes, the pilot again attempted to land on the dolly, this time from the opposite direction. He made two unsuccessful attempts but was unable to maintain a stabilized approach each time. Although the pilot had the option to land on the ramp, he persisted in attempting to land on the dolly. On his third attempt, he again landed partially on the dolly, and the helicopter rocked back and forth striking the ground with its tailskid, before violently climbing and pitching nose down, while rolling right. The helicopter spun 180° to the left and pitched up steeply, and the tail rotor and vertical stabilizer struck the ground and separated. The helicopter hit the ground left side low, bounced, and rotated another 360° before landing hard on its belly. The main rotor blades continued to spin and the engine continued to operate; the helicopter spun on its belly at a rate of about one revolution per second for more than 5 minutes, while gradually sliding about 530 ft along the ramp. The tailboom and horizontal stabilizer then separated, and the helicopter violently rolled onto its side, shed its main rotor blades, and came to rest. Onboard video showed that the pilot became incapacitated during the final ground collision. The passenger remained conscious after the impact and reached for the throttle on the pilot's collective control shortly after the helicopter started to spin, but the throttle position remained unchanged. He then attempted to brace himself against the glare shield, but he eventually became incapacitated after about 2 minutes due to his injuries, the forces imposed by the spinning helicopter, or both. He did not make any attempt to reach up for the engine-start selector or the fuel shutoff lever. Postaccident examination did not reveal any anomalies with the helicopter's airframe or engine that would have precluded normal operation. In the weeks preceding the accident, the pilot had expressed concern to multiple flight instructors that he was having difficulty adjusting to the flight characteristics of the helicopter. In particular, he found dolly-landings challenging. Although the pilot had many years of experience flying a Bell 407 helicopter, there were two significant differences between the Bell 407 and the accident helicopter. First, their main rotor systems rotated in opposite directions; therefore, the foot pedal inputs required to counteract changes in torque during takeoff and landing were opposite. (The pilot's difficulty adapting to this difference was evidenced during most of the previous takeoffs captured by the onboard video when the helicopter yawed significantly after lifting off.) Second, the tips of the landing skids, which were used as a visual reference during landing, were forward of the pilot in the Bell 407 but just aft of the pilot in the accident helicopter. This change in visual reference would have been particularly significant during dolly landings, which require landing on a specific point directly below the pilot's field of view. The pilot had received about 11 hours of flight instruction in the helicopter, and, despite the fact that his instructors advised him not to fly without an instructor, he opted to fly with a passenger instead of an instructor on the accident flight. Although the passenger held a helicopter rating, he was not an instructor or professional helicopter pilot and had about 180 hours total in helicopters. Furthermore, it was likely that he had little or no experience in the accident helicopter make and model. The pilot's instructors reported a mobility problem with the pilot's left arm that affected his ability to reach overhead, but this problem likely did not contribute to the accident, because he had no need to reach overhead during landing. Postmortem toxicology testing identified amlodipine, valsartan, and rosuvastatin as well as diphenhydramine at 0.538 ug/ml and alprazolam at less than 0.05 mg/l in the pilot's blood. The pilot had heart disease and hypertension and used amlodipine, valsartan, and rosuvastatin for their treatment; however, these conditions and medications most likely did not contribute to the accident as they do not affect judgment or decision-making. Alprazolam is a significant central nervous system (CNS) depressant with the lower end of the therapeutic range at 0.0060 mg/l. The exact amount of alprazolam in the pilot could not be determined by testing and may have been very low. The therapeutic range for diphenhydramine is 0.0250 to 0.1120 ug/ml. However, diphenhydramine undergoes postmortem redistribution, and postmortem central blood levels may increase by about three times. When divided by three or four, the pilot's postmortem level suggests that he had therapeutic levels at the time of the crash. Compared to other antihistamines, diphenhydramine causes marked sedation and is also a CNS depressant. In addition, it may cause altered mood and impaired cognitive and psychomotor performance. The use of two CNS depressants simultaneously typically results in cognitive impairment which is magnified well beyond the simple addition of the effects, even when the amount of one of them may be low. Therefore, the pilot's decision-making, judgment, and psychomotor performance were most likely impaired by the combination of CNS depressants, diphenhydramine and alprazolam.

Pilot At the time of his most recent FAA medical examination, the pilot reported hypertension and the use of medications including nebivolol (blood pressure medication), pantoprazole (heartburn medication), and rosuvastatin (cholesterol lowering medication). According to the autopsy performed by the County of San Diego Office of the Medical Examiner, the pilot's cause of death was multiple injuries, and the manner of death was accident. The autopsy report noted significant intracranial injuries with bilateral subdural and subarachnoid hemorrhage more pronounced on the right side and the base of the brain extending into the foramen magnum and cervical canal. Intraventricular hemorrhage without parenchymal contusions was also noted. In addition, hemorrhage of the anterior cervical ligament associated with fractures of the body of C6 (and possibly C7) with associated subdural hemorrhage surrounding the cervical spinal cord was identified. The pilot's heart was enlarged, and mild coronary artery disease with 50% stenosis was also described. Toxicology testing by the medical examiner detected amlodipine (0.34 mg/l) and alprazolam (less than 0.05 mg/l) in peripheral blood. Toxicology testing by the FAA's Bioaeronautical Sciences Research Laboratory, identified amlodipine, valsartan, rosuvastatin, and diphenhydramine (0.538 ug/ml) in heart blood. In addition, the FAA laboratory found alpha-hydroxyalprazolam (0.044 ug/ml) and salicylate in urine. Amlodipine and valsartan are blood pressure medications and, along with rosuvastatin, are generally considered non-impairing. Alpha-hydroxyalprazolam is a metabolite of alprazolam, a potentially impairing anxiety medication. Alprazolam is commonly marketed under the name Xanax, and it carries the warning: "Because of its CNS (central nervous system) depressant effects, patients receiving alprazolam tablets should be cautioned against engaging in hazardous occupations or activities requiring complete mental alertness such as operating machinery or driving a motor vehicle. For the same reason, patients should be cautioned about the simultaneous ingestion of alcohol and other CNS depressant drugs during treatment with alprazolam tablets." Diphenhydramine is a sedating antihistamine that has been shown to significantly impair performance at routine doses. Pilot-Rated Passenger The pilot-rated passenger reported no chronic medical problems and no medications at the time of his most recent FAA medical examination. According to the autopsy performed by the County of San Diego Office of the Medical Examiner, the pilot-rated passenger's cause of death was multiple injuries, and the manner of death was accident. His injuries included bilateral subdural and subarachnoid hemorrhages, ligamentous instability at C1/C2, and fracture at C6/C7 with associated subdural hemorrhage but without obvious spinal cord injury. In the torso, there was a fracture of the sternum along with multiple rib fractures, some associated with retroperitoneal hemorrhage. There were widely open fractures of both bones of the lower left leg. He was found to have an enlarged heart with thickened walls and minimal coronary artery disease. Toxicology testing by the FAA's Bioaeronautical Sciences Research Laboratory identified ranitidine (a non-impairing heartburn medication) in the pilot-rated passenger's urine. According to the U.S. Naval Observatory's Astronomical Applications Department, the altitude of the sun when viewed from Carlsbad at 1620 would have been 4.3°, with an azimuth (E of N) of 243.7°. The pilot was seated in the front right seat, and the pilot-rated passenger was seated in the front left seat. Pilot The pilot held a private pilot certificate with ratings for airplane single-engine land and sea, multiengine land, instrument airplane, and rotorcraft-helicopter. He also held a type rating for the Cessna Citation Jet (CE-525S). The pilot held a third-class medical certificate issued on January 19, 2015, with the limitation that he must have available glasses for near vision. No personal flight records were located for the pilot. At the time of his last medical application, he reported a total flight time of 25,000 hours, with 200 hours logged in the last 6 months. The pilot reported the same numbers on three other applications over the 5-year period preceding the accident, and 25,400 hours total time on his application dated January 18, 2011. His helicopter rating was issued in May 2001, at which time he reported on his rating application a total flight time of 14,000 hours in airplanes. The pilot had previously owned and flown a Cessna Citation business jet airplane and a Bell 407 helicopter. His 2001 helicopter checkride flight took place in a Bell 206B3. At the time of the accident, he was receiving recurrent training for the Citation, with the most recent flight 2 days before the accident. The pilot purchased the accident helicopter on October 29, 2015, and had flown demonstration and familiarization flights in it since September 20. According to the helicopter's flight logs, those flights totaled about 8.8 hours and were all conducted with a flight instructor present. The pilot then flew the helicopter with another instructor for an additional 2 hours on November 13. According to the two instructors who had flown with the pilot for the familiarization flights and the flight instructor who provided training in the Citation, the accident flight was the first time the pilot had flown in an AS350 without an instructor present. All had recommended that the pilot gain further instruction before flying without an instructor, and the pilot had concurred. The three instructors shared similar insights into the pilot's flying skills, reporting that, while he appeared to have extensive flying experience, he was anxious about the handling characteristics of the AS350 compared to the Bell 407, particularly during landing. The pilot said that he was having difficulty anticipating flight control forces because the helicopter controls felt "backwards" due to the opposing rotor direction of the AS350 compared to the Bell 407. Furthermore, he was having trouble landing on the dolly partly because the tips of the skids were just behind his seating location in the AS350, as opposed to the Bell 407, where he could see the skids just forward and below. Both helicopter instructors reported performing multiple dolly and simulated dolly landings with the pilot, stating that, although the pilot was not completely at ease, he was able to ultimately land on the dolly unaided. The pilot told the Citation instructor that, although he had practiced many landings in the helicopter, he still did not feel proficient and thought that the helicopter was very unstable close to the ground, especially when it was close to the dolly. One of the helicopter instructors reported that the pilot wanted to enable the helicopter's stability augmentation system (SAS) for landings because he had been told it would help his landings. The instructor stated that he wanted the pilot to be able to fly the helicopter proficiently without the use of the SAS. However, for demonstration purposes, they did two landings with the SAS enabled. During those attempts, the pilot appeared to be "fighting" against the SAS control inputs, with unsatisfactory results, and he did not understand how to use the SAS release button on the cyclic to override the SAS control inputs. Therefore, the pilot and instructor decided to turn the system off. Both helicopter instructors reported that the pilot appeared to have suffered an injury that restricted movement of his left arm. He could use his left arm to operate the flight controls and reach the lower sections of the flight panel, but he could not reach the upper controls, including the engine start selector panel, without the supportive aid of his right arm. One instructor stated that because of